Table of Contents
What does overexpression of genes mean?
(OH-ver-ek-SPRES) In biology, to make too many copies of a protein or other substance. Overexpression of certain proteins or other substances may play a role in cancer development.
How does overexpression of a gene work?
Gene overexpression is the process which leads to the abundant target protein expression subsequently. The process may be in the cell where the gene is originally located or in other expression systems.
Why is overexpression of genes bad?
Gene overexpression is the switching on of genes in aging cells. Most of these have been demonstrated in senescent human fibroblasts and are functionally associated with the degradation of the ECM and the production of cytokines (i.e., these are deleterious functions that will lead to tissue damage).
What causes increased gene expression?
Gene expression is influenced by numerous factors, including molecules within the cell, mutations causing dominant negative effects and haploinsufficiency, signaling molecules from surrounding cells and the environment, and epistasis. Various molecules within the cell modulate gene expression.
What influences gene expression?
The expression of genes in an organism can be influenced by the environment, including the external world in which the organism is located or develops, as well as the organism’s internal world, which includes such factors as its hormones and metabolism.
What is receptor overexpression?
Overexpressed receptors are frequently observed in cancer cells to assemble nutrients and to provide the needs for uncontrolled growth. In this chapter, we discuss the receptors generally overexpressed in lung cancer cells. Each receptor plays an important function at different stages of growth and tumor progression.
What causes gene amplification?
Gene amplification refers to an increase in the number of copies of the same gene rather than to an increase in its rate of transcription. It results from gene duplication that has been repeated many times over, producing from 100 to 1000 copies of the gene.
What is upregulation receptors?
Upregulation: An increase in the number of receptors on the surface of target cells, making the cells more sensitive to a hormone or another agent. For example, there is an increase in uterine oxytocin receptors in the third trimester of pregnancy, promoting the contraction of the smooth muscle of the uterus.
What happens during gene expression?
Gene expression is the process the cell uses to produce the molecule it needs by reading the genetic code written in the DNA. To do this, the cell interprets the genetic code, and for each group of three letters it adds one of the 20 different amino acids that are the basic units needed to build proteins.
What is gene expression in animals?
Gene expression is a fundamental life process providing a bridge between information encoded within a gene and a final functional gene product, such as a protein or non-coding RNA (ncRNA).
What factors increase gene expression?
In addition to drugs and chemicals, temperature and light are external environmental factors that may influence gene expression in certain organisms.
What is amplification mutation?
The amplification–mutagenesis model suggests a general mechanism by which selection may enhance the rate of genetic change during growth under strong selection without altering the rate or specificity of mutation. The model may be applicable to origin of some cancers and to the evolution of new genes.
What is upregulation and downregulation of genes?
In the biological context of organisms’ production of gene products, downregulation is the process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external stimulus. The complementary process that involves increases of such components is called upregulation.
Can misexpression of a gene product cause a mutant phenotype?
Overexpression or misexpression of a wild-type gene product, however, can also cause mutant phenotypes, providing geneticists with an alternative yet powerful tool to identify pathway components that might remain undetected using traditional loss-of-function analysis.
How do you suppress a phenotype caused by overexpression?
Phenotypes caused by targeted overexpression of a given gene therefore can be suppressed by mutations in a second gene or by overexpression of another gene, with the potential to identify direct physical interactors. Application in epistasis tests
What is overexpression of mutant genes?
Overexpression of mutant genes. As cloned genes became increasingly available in the 1980s, it became important to identify null phenotypes for these genes, but unfortunately it was not yet possible to create targeted deletions to infer gene function in most organisms.
How do you determine the mechanism of overexpression?
The primary test to distinguish the mechanism responsible for an overexpression phenotype is determining the loss-of-function phenotype of the gene of interest. Three outcomes can be envisioned: loss-of-function could cause either the opposite phenotype of overexpression, the same phenotype, or no phenotype.